Just want to give my 2c on why we have to live with this installer (I haven’t had problems with mine, but understand people that do).
Basically, this is Microsoft not Asobo’s fault. Since MS insists on having their games via the MS Store, there would be no way to have the sim be as pluggable and moddable as previous sims have been. When this sim started development, no mods were permitted on the store, and even the mod support that exists now is very managed. With all flight sims, players have traditionally been able to modify config files, install plugins by dumping them into a folder, etc. Therefore, the ingenious idea by Asobo to separate the installer from the store, to keep that independant, and let anyone mess with the content files.
The problem here of course is that making a downloader / installer is actually quite difficult for this scale of game, and whilst it has been solved by Steam and other platforms, they likely have large teams dedicated to this. Asobo had to take time out of developing their flight sim, just to get the installer right, and of course they didn’t catch several edge conditions that have come up. This is also what prevented them from having a preload. They could have probably done the last part, but why spend months implementing a feature that would only be active for a few weeks at most.
Just providing a likely explanation for this fiasco, and hoping everyone would just turn their rage at trying to get Microsoft to forget about their store and just publish their games on the other storefronts.